1. Field of the Invention
The present invention relates to an image forming method for a copier, a printer, or the like, in which an adhesive portion is formed on a recording material using an electrophotographic process with the aid of an adhesive toner having a function as an adhesive for the sealing of a document or the like as well as an image forming toner.
2. Related Background Art
Conventionally, when a document with confidential contents requiring sealing, such as a pay statement is produced, a preprinted sheet is prepared, on which a format such as ruled lines is printed by a printing machine, and a pressure bonding adhesive for sealing is applied to an adhesive portion of the preprinted sheet. Only recorded data such as letters, and numbers are variably outputted using an electrophotographic apparatus. After that, the preprinted sheet is folded and contact-bonded by a post-treatment device, and the document is thereby sealed. This method has been widely adopted.
However, there are problems in that it takes a long time to prepare the preprinted sheet having formed thereon the format by the printing machine and the adhesive portion by the adhesive, and in that high cost and low efficiency are inevitable in a field of application requiring a small number of preprinted sheets.
In view of the above-mentioned problems, JP S61-274764 A and JP H09-110051 A each discloses a method of sealing a document. According to this method, with the aid of an electrophotographic process, a format is formed and an adhesive portion is formed using a toner for forming recorded data as an adhesive. The adhesive portion is heated and pressurized to soften the toner to develop adhesiveness. As a result, the document is sealed.
Further, JP 2004-126229 A discloses a method for sealing a document by adding a pressure sensitive adhesive to a toner, forming an adhesive portion by an electrophotographic apparatus, and bonding the adhesive portion by the application of a pressure by a pressure bonding device.
However, due to heat and pressure at the time of adhesion, the toner forming an image as well as the toner serving as an adhesive develops adhesiveness, and part of the toner image is transferred onto a surface of the sheet opposed thereto when the toner used to form the image is used as the adhesive. As a result, the toner image deteriorates. Therefore, only the adhesive portion needs to be heated and pressurized locally, which requires a special post-treatment device or a manual operation step. Thus, problems are caused in terms of the cost of the device and the efficiency.
The method of using toner to which a pressure sensitive adhesive is added requires a large-sized pressure bonding device as a post-treatment device, so problems are caused in terms of the space and cost of the device.